I'm not sure if it is reasonable. In common sense, we can still
start our system even if we have a corrupt data disk .And also ,if in
data center we carelessly attatch a corrupt volumn to all the guest, it
will result in all guests fail to boot .

I suggest to automatically detach a disk if it can't be found and
just give out a warning.Please let me know your opinion about if it is a
bug or a feature.Thanks.